jdk/src/solaris/classes/sun/nio/cs/ext/CompoundTextSupport.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/solaris/classes/sun/nio/cs/ext/CompoundTextSupport.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,548 @@
+/*
+ * Copyright 2001-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package sun.nio.cs.ext;
+
+import java.util.Collections;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.nio.charset.*;
+
+final class CompoundTextSupport {
+
+    private static final class ControlSequence {
+
+        final int hash;
+        final byte[] escSequence;
+        final byte[] encoding;
+
+        ControlSequence(byte[] escSequence) {
+            this(escSequence, null);
+        }
+        ControlSequence(byte[] escSequence, byte[] encoding) {
+            if (escSequence == null) {
+                throw new NullPointerException();
+            }
+
+            this.escSequence = escSequence;
+            this.encoding = encoding;
+
+            int hash = 0;
+            int length = escSequence.length;
+
+            for (int i = 0; i < escSequence.length; i++) {
+                hash += (((int)escSequence[i]) & 0xff) << (i % 4);
+            }
+            if (encoding != null) {
+                for (int i = 0; i < encoding.length; i++) {
+                    hash += (((int)encoding[i]) & 0xff) << (i % 4);
+                }
+                length += 2 /* M L */ + encoding.length + 1 /* 0x02 */;
+            }
+
+            this.hash = hash;
+
+            if (MAX_CONTROL_SEQUENCE_LEN < length) {
+                MAX_CONTROL_SEQUENCE_LEN = length;
+            }
+        }
+
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (!(obj instanceof ControlSequence)) {
+                return false;
+            }
+            ControlSequence rhs = (ControlSequence)obj;
+            if (escSequence != rhs.escSequence) {
+                if (escSequence.length != rhs.escSequence.length) {
+                    return false;
+                }
+                for (int i = 0; i < escSequence.length; i++) {
+                    if (escSequence[i] != rhs.escSequence[i]) {
+                        return false;
+                    }
+                }
+            }
+            if (encoding != rhs.encoding) {
+                if (encoding == null || rhs.encoding == null ||
+                    encoding.length != rhs.encoding.length)
+                {
+                    return false;
+                }
+                for (int i = 0; i < encoding.length; i++) {
+                    if (encoding[i] != rhs.encoding[i]) {
+                        return false;
+                    }
+                }
+            }
+            return true;
+        }
+
+        public int hashCode() {
+            return hash;
+        }
+
+        ControlSequence concatenate(ControlSequence rhs) {
+            if (encoding != null) {
+                throw new IllegalArgumentException
+                    ("cannot concatenate to a non-standard charset escape " +
+                     "sequence");
+            }
+
+            int len = escSequence.length + rhs.escSequence.length;
+            byte[] newEscSequence = new byte[len];
+            System.arraycopy(escSequence, 0, newEscSequence, 0,
+                             escSequence.length);
+            System.arraycopy(rhs.escSequence, 0, newEscSequence,
+                             escSequence.length, rhs.escSequence.length);
+            return new ControlSequence(newEscSequence, rhs.encoding);
+        }
+    }
+
+    static int MAX_CONTROL_SEQUENCE_LEN;
+
+    /**
+     * Maps a GL or GR escape sequence to an encoding.
+     */
+    private static final Map sequenceToEncodingMap;
+
+    /**
+     * Indicates whether a particular encoding wants the high bit turned on
+     * or off.
+     */
+    private static final Map highBitsMap;
+
+    /**
+     * Maps an encoding to an escape sequence. Rather than manage two
+     * converters in CharToByteCOMPOUND_TEXT, we output escape sequences which
+     * modify both GL and GR if necessary. This makes the output slightly less
+     * efficient, but our code much simpler.
+     */
+    private static final Map encodingToSequenceMap;
+
+    /**
+     * The keys of 'encodingToSequenceMap', sorted in preferential order.
+     */
+    private static final List encodings;
+
+    static {
+        HashMap tSequenceToEncodingMap = new HashMap(33, 1.0f);
+        HashMap tHighBitsMap = new HashMap(31, 1.0f);
+        HashMap tEncodingToSequenceMap = new HashMap(21, 1.0f);
+        ArrayList tEncodings = new ArrayList(21);
+
+        if (!(isEncodingSupported("US-ASCII") &&
+              isEncodingSupported("ISO-8859-1")))
+        {
+            throw new ExceptionInInitializerError
+                ("US-ASCII and ISO-8859-1 unsupported");
+        }
+
+        ControlSequence leftAscii = // high bit off, leave off
+            new ControlSequence(new byte[] { 0x1B, 0x28, 0x42 });
+        tSequenceToEncodingMap.put(leftAscii, "US-ASCII");
+        tHighBitsMap.put(leftAscii, Boolean.FALSE);
+
+        {
+            ControlSequence rightAscii = // high bit on, turn off
+                new ControlSequence(new byte[] { 0x1B, 0x29, 0x42 });
+            tSequenceToEncodingMap.put(rightAscii, "US-ASCII");
+            tHighBitsMap.put(rightAscii, Boolean.FALSE);
+        }
+
+        {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x41 });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-1");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-1", fullSet);
+            tEncodings.add("ISO-8859-1");
+        }
+        if (isEncodingSupported("ISO-8859-2")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x42 });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-2");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-2", fullSet);
+            tEncodings.add("ISO-8859-2");
+        }
+        if (isEncodingSupported("ISO-8859-3")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x43 });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-3");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-3", fullSet);
+            tEncodings.add("ISO-8859-3");
+        }
+        if (isEncodingSupported("ISO-8859-4")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x44 });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-4");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-4", fullSet);
+            tEncodings.add("ISO-8859-4");
+        }
+        if (isEncodingSupported("ISO-8859-5")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x4C });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-5");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-5", fullSet);
+            tEncodings.add("ISO-8859-5");
+        }
+        if (isEncodingSupported("ISO-8859-6")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x47 });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-6");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-6", fullSet);
+            tEncodings.add("ISO-8859-6");
+        }
+        if (isEncodingSupported("ISO-8859-7")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x46 });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-7");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-7", fullSet);
+            tEncodings.add("ISO-8859-7");
+        }
+        if (isEncodingSupported("ISO-8859-8")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x48 });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-8");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-8", fullSet);
+            tEncodings.add("ISO-8859-8");
+        }
+        if (isEncodingSupported("ISO-8859-9")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x4D });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-9");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-9", fullSet);
+            tEncodings.add("ISO-8859-9");
+        }
+        if (isEncodingSupported("JIS_X0201")) {
+            ControlSequence glLeft = // high bit off, leave off
+                new ControlSequence(new byte[] { 0x1B, 0x28, 0x4A });
+            ControlSequence glRight = // high bit off, turn on
+                new ControlSequence(new byte[] { 0x1B, 0x28, 0x49 });
+            ControlSequence grLeft = // high bit on, turn off
+                new ControlSequence(new byte[] { 0x1B, 0x29, 0x4A });
+            ControlSequence grRight = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x29, 0x49 });
+            tSequenceToEncodingMap.put(glLeft, "JIS_X0201");
+            tSequenceToEncodingMap.put(glRight, "JIS_X0201");
+            tSequenceToEncodingMap.put(grLeft, "JIS_X0201");
+            tSequenceToEncodingMap.put(grRight, "JIS_X0201");
+            tHighBitsMap.put(glLeft, Boolean.FALSE);
+            tHighBitsMap.put(glRight, Boolean.TRUE);
+            tHighBitsMap.put(grLeft, Boolean.FALSE);
+            tHighBitsMap.put(grRight, Boolean.TRUE);
+
+            ControlSequence fullSet = glLeft.concatenate(grRight);
+            tEncodingToSequenceMap.put("JIS_X0201", fullSet);
+            tEncodings.add("JIS_X0201");
+        }
+        if (isEncodingSupported("X11GB2312")) {
+            ControlSequence leftHalf =  // high bit off, leave off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x28, 0x41 });
+            ControlSequence rightHalf = // high bit on, turn off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x29, 0x41 });
+            tSequenceToEncodingMap.put(leftHalf, "X11GB2312");
+            tSequenceToEncodingMap.put(rightHalf, "X11GB2312");
+            tHighBitsMap.put(leftHalf, Boolean.FALSE);
+            tHighBitsMap.put(rightHalf, Boolean.FALSE);
+
+            tEncodingToSequenceMap.put("X11GB2312", leftHalf);
+            tEncodings.add("X11GB2312");
+        }
+        if (isEncodingSupported("x-JIS0208")) {
+            ControlSequence leftHalf = // high bit off, leave off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x28, 0x42 });
+            ControlSequence rightHalf = // high bit on, turn off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x29, 0x42 });
+            tSequenceToEncodingMap.put(leftHalf, "x-JIS0208");
+            tSequenceToEncodingMap.put(rightHalf, "x-JIS0208");
+            tHighBitsMap.put(leftHalf, Boolean.FALSE);
+            tHighBitsMap.put(rightHalf, Boolean.FALSE);
+
+            tEncodingToSequenceMap.put("x-JIS0208", leftHalf);
+            tEncodings.add("x-JIS0208");
+        }
+        if (isEncodingSupported("X11KSC5601")) {
+            ControlSequence leftHalf = // high bit off, leave off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x28, 0x43 });
+            ControlSequence rightHalf = // high bit on, turn off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x29, 0x43 });
+            tSequenceToEncodingMap.put(leftHalf, "X11KSC5601");
+            tSequenceToEncodingMap.put(rightHalf, "X11KSC5601");
+            tHighBitsMap.put(leftHalf, Boolean.FALSE);
+            tHighBitsMap.put(rightHalf, Boolean.FALSE);
+
+            tEncodingToSequenceMap.put("X11KSC5601", leftHalf);
+            tEncodings.add("X11KSC5601");
+        }
+
+        // Encodings not listed in Compound Text Encoding spec
+
+        // Esc seq: -b
+        if (isEncodingSupported("ISO-8859-15")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x62 });
+            tSequenceToEncodingMap.put(rightHalf, "ISO-8859-15");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("ISO-8859-15", fullSet);
+            tEncodings.add("ISO-8859-15");
+        }
+        // Esc seq: -T
+        if (isEncodingSupported("TIS-620")) {
+            ControlSequence rightHalf = // high bit on, leave on
+                new ControlSequence(new byte[] { 0x1B, 0x2D, 0x54 });
+            tSequenceToEncodingMap.put(rightHalf, "TIS-620");
+            tHighBitsMap.put(rightHalf, Boolean.TRUE);
+
+            ControlSequence fullSet = leftAscii.concatenate(rightHalf);
+            tEncodingToSequenceMap.put("TIS-620", fullSet);
+            tEncodings.add("TIS-620");
+        }
+        if (isEncodingSupported("JIS_X0212-1990")) {
+            ControlSequence leftHalf = // high bit off, leave off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x28, 0x44 });
+            ControlSequence rightHalf = // high bit on, turn off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x29, 0x44 });
+            tSequenceToEncodingMap.put(leftHalf, "JIS_X0212-1990");
+            tSequenceToEncodingMap.put(rightHalf, "JIS_X0212-1990");
+            tHighBitsMap.put(leftHalf, Boolean.FALSE);
+            tHighBitsMap.put(rightHalf, Boolean.FALSE);
+
+            tEncodingToSequenceMap.put("JIS_X0212-1990", leftHalf);
+            tEncodings.add("JIS_X0212-1990");
+        }
+        if (isEncodingSupported("X11CNS11643P1")) {
+            ControlSequence leftHalf = // high bit off, leave off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x28, 0x47 });
+            ControlSequence rightHalf = // high bit on, turn off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x29, 0x47 });
+            tSequenceToEncodingMap.put(leftHalf, "X11CNS11643P1");
+            tSequenceToEncodingMap.put(rightHalf, "X11CNS11643P1");
+            tHighBitsMap.put(leftHalf, Boolean.FALSE);
+            tHighBitsMap.put(rightHalf, Boolean.FALSE);
+
+            tEncodingToSequenceMap.put("X11CNS11643P1", leftHalf);
+            tEncodings.add("X11CNS11643P1");
+        }
+        if (isEncodingSupported("X11CNS11643P2")) {
+            ControlSequence leftHalf = // high bit off, leave off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x28, 0x48 });
+            ControlSequence rightHalf = // high bit on, turn off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x29, 0x48 });
+            tSequenceToEncodingMap.put(leftHalf, "X11CNS11643P2");
+            tSequenceToEncodingMap.put(rightHalf, "X11CNS11643P2");
+            tHighBitsMap.put(leftHalf, Boolean.FALSE);
+            tHighBitsMap.put(rightHalf, Boolean.FALSE);
+
+            tEncodingToSequenceMap.put("X11CNS11643P2", leftHalf);
+            tEncodings.add("X11CNS11643P2");
+        }
+        if (isEncodingSupported("X11CNS11643P3")) {
+            ControlSequence leftHalf = // high bit off, leave off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x28, 0x49 });
+            ControlSequence rightHalf = // high bit on, turn off
+                new ControlSequence(new byte[] { 0x1B, 0x24, 0x29, 0x49 });
+            tSequenceToEncodingMap.put(leftHalf, "X11CNS11643P3");
+            tSequenceToEncodingMap.put(rightHalf, "X11CNS11643P3");
+            tHighBitsMap.put(leftHalf, Boolean.FALSE);
+            tHighBitsMap.put(rightHalf, Boolean.FALSE);
+
+            tEncodingToSequenceMap.put("X11CNS11643P3", leftHalf);
+            tEncodings.add("X11CNS11643P3");
+        }
+        // Esc seq: %/2??SUN-KSC5601.1992-3
+        if (isEncodingSupported("x-Johab")) {
+            // 0x32 looks wrong. It's copied from the Sun X11 Compound Text
+            // support code. It implies that all Johab characters comprise two
+            // octets, which isn't true. Johab supports the ASCII/KS-Roman
+            // characters from 0x21-0x7E with single-byte representations.
+            ControlSequence johab = new ControlSequence(
+                new byte[] { 0x1b, 0x25, 0x2f, 0x32 },
+                new byte[] { 0x53, 0x55, 0x4e, 0x2d, 0x4b, 0x53, 0x43, 0x35,
+                             0x36, 0x30, 0x31, 0x2e, 0x31, 0x39, 0x39, 0x32,
+                             0x2d, 0x33 });
+            tSequenceToEncodingMap.put(johab, "x-Johab");
+            tEncodingToSequenceMap.put("x-Johab", johab);
+            tEncodings.add("x-Johab");
+        }
+        // Esc seq: %/2??SUN-BIG5-1
+        if (isEncodingSupported("Big5")) {
+            // 0x32 looks wrong. It's copied from the Sun X11 Compound Text
+            // support code. It implies that all Big5 characters comprise two
+            // octets, which isn't true. Big5 supports the ASCII/CNS-Roman
+            // characters from 0x21-0x7E with single-byte representations.
+            ControlSequence big5 = new ControlSequence(
+                new byte[] { 0x1b, 0x25, 0x2f, 0x32 },
+                new byte[] { 0x53, 0x55, 0x4e, 0x2d, 0x42, 0x49, 0x47, 0x35,
+                             0x2d, 0x31 });
+            tSequenceToEncodingMap.put(big5, "Big5");
+            tEncodingToSequenceMap.put("Big5", big5);
+            tEncodings.add("Big5");
+        }
+
+        sequenceToEncodingMap =
+            Collections.unmodifiableMap(tSequenceToEncodingMap);
+        highBitsMap = Collections.unmodifiableMap(tHighBitsMap);
+        encodingToSequenceMap =
+            Collections.unmodifiableMap(tEncodingToSequenceMap);
+        encodings = Collections.unmodifiableList(tEncodings);
+    }
+
+    private static boolean isEncodingSupported(String encoding) {
+        try {
+            if (Charset.isSupported(encoding))
+                return true;
+        } catch (IllegalArgumentException x) { }
+        return (getDecoder(encoding) != null &&
+                getEncoder(encoding) != null);
+    }
+
+
+    // For Decoder
+    static CharsetDecoder getStandardDecoder(byte[] escSequence) {
+        return getNonStandardDecoder(escSequence, null);
+    }
+    static boolean getHighBit(byte[] escSequence) {
+        Boolean bool = (Boolean)highBitsMap.get
+            (new ControlSequence(escSequence));
+        return (bool == Boolean.TRUE);
+    }
+    static CharsetDecoder getNonStandardDecoder(byte[] escSequence,
+                                                       byte[] encoding) {
+        return getDecoder((String)sequenceToEncodingMap.get
+            (new ControlSequence(escSequence, encoding)));
+    }
+    static CharsetDecoder getDecoder(String enc) {
+        if (enc == null) {
+            return null;
+        }
+        Charset cs = null;
+        try {
+            cs = Charset.forName(enc);
+        } catch (IllegalArgumentException e) {
+            Class cls;
+            try {
+                cls = Class.forName("sun.awt.motif." + enc);
+            } catch (ClassNotFoundException ee) {
+                return null;
+            }
+            try {
+                cs = (Charset)cls.newInstance();
+            } catch (InstantiationException ee) {
+                return null;
+            } catch (IllegalAccessException ee) {
+                return null;
+            }
+        }
+        try {
+            return cs.newDecoder();
+        } catch (UnsupportedOperationException e) {}
+        return null;
+    }
+
+
+    // For Encoder
+    static byte[] getEscapeSequence(String encoding) {
+        ControlSequence seq = (ControlSequence)
+            encodingToSequenceMap.get(encoding);
+        if (seq != null) {
+            return seq.escSequence;
+        }
+        return null;
+    }
+    static byte[] getEncoding(String encoding) {
+        ControlSequence seq = (ControlSequence)
+            encodingToSequenceMap.get(encoding);
+        if (seq != null) {
+            return seq.encoding;
+        }
+        return null;
+    }
+    static List getEncodings() {
+        return encodings;
+    }
+    static CharsetEncoder getEncoder(String enc) {
+        if (enc == null) {
+            return null;
+        }
+        Charset cs = null;
+        try {
+            cs = Charset.forName(enc);
+        } catch (IllegalArgumentException e) {
+            Class cls;
+            try {
+                cls = Class.forName("sun.awt.motif." + enc);
+            } catch (ClassNotFoundException ee) {
+                return null;
+            }
+            try {
+                cs = (Charset)cls.newInstance();
+            } catch (InstantiationException ee) {
+                return null;
+            } catch (IllegalAccessException ee) {
+                return null;
+            }
+        }
+        try {
+            return cs.newEncoder();
+        } catch (Throwable e) {}
+        return null;
+    }
+
+    // Not an instantiable class
+    private CompoundTextSupport() {}
+}